Pathophysiology

Question 1

Types of A. Fib

1. Paroxysmal:
2. Persistent:
3. Permanent:
4. Lone Afib:

Answer 1

1. Paroxysmal: it terminates spontaneously & recurs
2. Persistent: > 7 days requiring CV
3. Permanent: > 1y, failed CV or futile
4. Lone Afib: pt is young (

Question 2

Cause of A.Fib

Answer 2

MI
CHF
HTN
Valvular disease
ETOH
Hyperthyroidism

Question 3

A. Fib/flutter management

Answer 3

1. Rhythm control: converting a. fib back to normal (CV). Easy to MD in young & healthy pt
2. Rate Control: used for pt who failed Rhythm Control, have permanent a.fib, or thought to have no chance of MD normal sinus rhythm after CV
3. Clot control: irrespective of which stragetry: anticoagulation to prevent stroke.

Question 4

Describe Rhythm Control Strategy

Answer 4

• Cardioversion: electrical or pharmacologic
• If A.fib > 48H old: Echo 1st:
• if clot => anticoagulation 3 wks prior => CV => 4 weeks anticoagulation
• If no clot => start IV anticoagulation STAT => rec 4 weeks anticoagulation

Question 5

What agents are use for Rhythm Control

Answer 5

FDA PI

• Flecainide
• Dofetilide
• Amiodarone
• Propafenone
• Ibutilide

Question 6

Describe Rate Control strategy

Answer 6

Blocking some of the atrial electrical impulse at AV node before they reach the ventricle by AV blockers

Question 7

What agents are use for Rate Control

Answer 7

ABCD => 1. Amiodarone 2. BB 3. CCB (NDHP) 4. Digoxin

• 1st Line: BB and NDHP CCB
• PEM => Propranolol; Esmolol; Metoprolol
• CCB => Verampamil; Diltiazem
• Alternative: Amiodarone or digoxin can be added into the 1st line.
• Can be done in both acute setting (IV) or chronic setting (PO)

Question 8

Describe Clot Control Management

- Cause of clot:

Answer 8

• To prevent thromboembolic stroke

- Cause: blood stasis in L atrium appendage

Question 9

What agents use for Clot Control

Answer 9

• Warfarin: VKA
• Dabigatran: Pradaxa
• Rivaroxaban: Xarelto

Question 10

A. Fib CHADS2 Score

New version of CHADS2 score?

Answer 10

To assess stroke risk in A.fib

• CHF: 1 pt
• HTN: 1 pt
• Age > 75: 1 pt
• DM: 1 pt
• Stroke/TIA: 2 pts

Newer version: CHA2DS2-VAS

Question 11

What is the AHA/ACC Guidelines for CHADS2 of 0, 1, and 2 points

Answer 11

• 0: ASA
• 1: ASA or PO anticoagulation
• 2: PO anticoagulation

Question 12

What is the ACCP guideline for CHADS2 of 0, 1, and 2

Answer 12

• 0: No therapy rec but pt can be on ASA

- 1 or more: PO anticoagulation

Question 13

Describes different phases of action potential

Answer 13

• 0: Depolarization/Rapid Na entry (QRS complex for ventricular depolarization
• 1: Ca++ entry => Contraction occurs
• 2: Plateau phase => Ca++ channels are balanced by outward K current
• 3: Repolarization (T-wave)
• 4: Na+ moves out of the cell and K moves into the cells.